Due date extension for GST compliance under section 39(6) read with section 168, deferring the prior deadline. Amends Notification No. 66/2018-Central Tax by substituting the earlier prescribed date with a later date, under the powers conferred by sub section (6) of section 39 read with section 168 of the Central Goods and Services Tax Act, 2017, thereby directly replacing the deadline language in the principal notification.